Rainbow Electronics MAX1231 - Manual (Page 9)

MAX1227/MAX1229/MAX1231
12-Bit 300ksps ADCs with FIFO,
Temp Sensor, Internal Reference
_______________________________________________________________________________________ 9
Detailed Description
The MAX1227/MAX1229/MAX1231 are low-power, seri-
al-output, multichannel ADCs with temperature-sensing
capability for temperature-control, process-control, and
monitoring applications. These 12-bit ADCs have inter-
nal track and hold (T/H) circuitry that supports single-
ended and fully differential inputs. Data is converted
from an internal temperature sensor or analog voltage
sources in a variety of channel and data-acquisition
configurations. Microprocessor (µP) control is made
easy through a 3-wire SPI/QSPI/MICROWIRE-compatible
serial interface.
Figure 2 shows a simplified functional diagram of the
MAX1227/MAX1229/MAX1231 internal architecture.
The MAX1227 has eight single-ended analog input
channels or four differential channels. The MAX1229
has 12 single-ended analog input channels or six differ-
ential channels. The MAX1231 has 16 single-ended
analog input channels or eight differential channels.
SCLK
DIN
DOUT
CS
t DH
t DOE
t DS
t CH t CSS
t CP t CSH
t
CSH
t
CSS
t DOD
t DOT
Figure 1. Detailed Serial-Interface Timing Diagram
12-BIT
SAR
ADC
CONTROL
SERIAL
INTERFACE
OSCILLATOR
FIFO AND
ACCUMULATOR
T/H
TEMP
SENSE
REF-
CNVST
SCLK
CS
DIN
EOC
DOUT
AIN15
AIN1
AIN2
INTERNAL
REFERENCE
REF+
MAX1227
MAX1229
MAX1231
Figure 2. Functional Diagram